Method and system for compensating thermally induced motion of probe cards
AssigneeFormFactor, Inc.
InventorGaetan L. Mathieu
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Abstract
The present invention discloses a method and system compensating for thermally induced motion of probe cards used in testing die on a wafer. A probe card incorporating temperature control devices to maintain a uniform temperature throughout the thickness of the probe card is disclosed. A probe card incorporating bi-material stiffening elements which respond to changes in temperature in such a way as to counteract thermally induced motion of the probe card is disclosed including rolling elements, slots and lubrication. Various means for allowing radial expansion of a probe card to prevent thermally induced motion of the probe card are also disclosed. A method for detecting thermally induced movement of the probe card and moving the wafer to compensate is also disclosed.
Claims28
A method for adjusting a probe card, comprising:
- placing a probe card in a prober;
- measuring a first distance from a known position to a position of said probe card;
- comparing via microprocessor means said first distance to a second distance to determine a variance therebetween;
- and,
- when said microprocessor determines said variance exceeds a determined value, electrically signally means for transmitting energy to said probe card to selectively deflect said probe card to control the geometric planarity of said probe card.
A system for adjusting geometric planarity of a probe card, comprising:
- a prober for receiving a probe card;
- means for measuring a distance indicating a position of said probe card;
- computer means for comparing said first distance to a second distance to determine a variance therebetween;
- and
- means for electrically signaling in response to said variance exceeding a value, said means for signally transmitting a signal to activate means for transmitting energy to said probe card to selectively deflect said probe card to control the geometric planarity of said probe card.
A method of using a probe card, said method comprising:
- bringing a probe card to within an initial distance of an electronic device to be tested;
- monitoring an actual distance of said probe card from said electronic device;
- and
- adjusting said actual distance if said actual distance becomes smaller or greater than a predetermined range of allowable distances,
- wherein said method further comprises testing said electronic device, and said monitoring step and said adjusting step are performed at least in part during said testing step.
A method of using a probe card, said method comprising:
- bringing a probe card to within an initial distance of an electronic device to be tested;
- monitoring an actual distance of said probe card from said electronic device;
- and
- adjusting said actual distance if said actual distance becomes smaller or greater than a predetermined range of allowable distances,
- wherein said adjusting step comprises controlling an energy transmissive device disposed adjacent said probe card.
A method of using a probe card, said method comprising:
- bringing a probe card to within an initial distance of an electronic device to be tested;
- monitoring an actual distance of said probe card from said electronic device;
- and
- adjusting said actual distance if said actual distance becomes smaller or greater than a predetermined range of allowable distances,
- wherein said adjusting step comprises heating a portion of said probe card.
A method of using a probe card, said method comprising:
- bringing a probe card to within an initial distance of an electronic device to be tested;
- monitoring an actual distance of said probe card from said electronic device;
- and
- adjusting said actual distance if said actual distance becomes smaller or greater than a predetermined range of allowable distances,
- wherein said adjusting step comprises:
- determining whether to heat or cool a portion of said probe card, and
- heating or cooling said portion of said probe card in accordance with said determining step.
Dependencies are inferred from the claim text.